The young and the reckless.

Top Line: Women with favorable ER(+) breast cancer with no or limited sentinel nodal disease have such an indolent disease processes that we often don’t employ aggressive therapies.

The Study: One exception to this can be very young women, ages 40 years or younger, who are known to suffer more aggressive tumor biologies. The Young Women's Breast Cancer Study prospectively enrolled over 1300 such young women with ER(+) stage I-III breast cancer. This analysis questioned if the tried and true Oncotype DX risk score can help us risk stratify treatment for women even this young and even with N1 disease. Oncotype scores were obtained on 509 (39%) fresh or banked tissue specimens. Of these, roughly 60% were N0 and 40% N1. Indeed, categorizing per TAILORx risk levels, scores indeed predicted risk of distant recurrence at six years for those with N0 disease: 94% if <11, 97% if 11-25, and 85% if ≥26. The bigger news is that it did the same for those with N1 disease: 92% if <11, 85% if 11-25, and 71% if ≥26. Now, most of these scores were obtained post-hoc meaning over half of women received chemo for N0 disease and almost all received chemo for N1 disease. How did this impact outcomes? On multivariate analysis, receipt of chemo for either N0 or N1 disease was not associated with distant recurrence while Oncotype score was.

TBL: Omitting chemo in selected young women with N1 breast cancer may not be as reckless as you think, particularly in those with very low Oncotype scores <11. | Poorvu, J Clin Oncol 2019